How to debug "Uncaught (in promise)" error


in my app I’m getting this error:

Uncaught (in promise): [object Object]
at c (http://localhost:8100/build/polyfills.js:3:19132)
at http://localhost:8100/build/polyfills.js:3:18554
at http://localhost:8100/build/polyfills.js:3:20622
at t.invoke (http://localhost:8100/build/polyfills.js:3:14356)
at Object.onInvoke (http://localhost:8100/build/vendor.js:4247:33)
at t.invoke (http://localhost:8100/build/polyfills.js:3:14296)
at (http://localhost:8100/build/polyfills.js:3:9523)
at http://localhost:8100/build/polyfills.js:3:19622
at t.invokeTask (http://localhost:8100/build/polyfills.js:3:15040)
at Object.onInvokeTask (http://localhost:8100/build/vendor.js:4238:33)

I’ve been looking for the source of the error for 2 hours, and I can’t find it. I have thousands of lines of code, with some processes running in background, so it’s really hard to find the exact promise that is uncaught. Because of polyfills, the stacktrace is completely useless.

Is there any way to debug this so I can find where is that promise that isn’t caught?